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Mounting a jib into a truckbed

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denton adkinson
Mounting a jib into a truckbed
on Jul 2, 2009 at 8:46:35 pm

I've got an Ez-Fx jib with extension, cameraturret PT24 pan/ tilt head and shooting with the Hpx-500. My plan is to mount the jib in the back of a truck and shoot some beautiful footage of motorcycles driving on the road for a client.

My problem is putting the jib in the truck, I get an unbelievable amount of vibration that transfers itself to the the camera head. I strapped down the jib base to the truck bed and it felt stable, but the camera head looked like it was going to vibrate off.

We don't have the budget to rent a crew with adequate equipment to get the shots for us, so I'm wondering if anyone can help me think of a method to reduce the vibrations from the truck to the jib head.

My first thought was to put a number of blankets between the truck bed and the jib base to try to lessen the vibrations.

I would be most appreciative if some of those wiser than I would share their ideas. If anyone has done something similar, I would love to hear about it, or see it.

Thanks in advance,

Denton


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Rick Amundson
Re: Mounting a jib into a truckbed
on Jul 3, 2009 at 12:03:46 pm

One "less expensive" alternative is to rent an optical stabilizing lens. They are not the cheapest lenses to rent, but they work well.

Best of luck!

Rick Amundson
Producer/Director/DP
Screenscape Studios
Bravo Romeo Entertainment
http://www.screenscapestudios.com
http://www.bravoromeo.com
http://www.indeliblemovie.com


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Richard Herd
Re: Mounting a jib into a truckbed
on Jul 4, 2009 at 1:19:47 am

Also search the cow for motion tracking, especially in the After Effects forum. Basically, motion tracking means the software will stabilize the shot. Fancy software, but not an unreasonable price. Coupled with a stabilizing lens, your footage will be smooth. If you're posting the footage too, no big deal, but if you have to turn the footage over to an edit house, consider motion tracking the footage first, then handing it over.

Motion tracking has limits, and I'm no expert.


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Todd Terry
Re: Mounting a jib into a truckbed
on Jul 4, 2009 at 5:36:32 am

That's good advice for fixing the shot... but I be just as worried if not moreso about getting the shot. If the vibration is as bad as you say ("...the camera head looked like it was going to vibrate off") that just can't be good for the camera.

In the "olden days" (Betacam era and earlier), the cameras were full of circuit boards that could fairly easily become unseated, thus vibration wasa real no-no. Now, cameras aren't designed quite like that anymore, but I'm sure vibration still isn't good for them.

Sounds like you've gone to good effort to attach the jib as securely as possible to the truck bed. That might actually be part of the probem. If the bazooka (or whatever stand the jib is riding on) is bolted down firm to the bed, it is simply transferring all the truck vibration straight to the cam head. Is there any way to dampen that? I'm thinking something like a thick rubber mat (like a bar mat) between the mounting points might help matters a little. Probably not completey, but perhaps some.



T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com






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denton adkinson
Re: Mounting a jib into a truckbed
on Jul 4, 2009 at 2:51:22 pm

Guys,

Thanks for the input.

I have tried stabilizing the test footage in Shake. It produced moderately acceptable results, but there was a wavy line in the footage. It looked like the background was being morphed between frames. I guess the footage was just too shaky even for Shake (no pun intended).

I've thought to dampen the vibration with something between the jib base and the truck bed. A rubber bar mat might be an idea considering its thickness. I might look around and see where I can locate one. I was originally thinking of some thick blankets, but perhaps the best option would be to use both and strap the jib to it.

Thanks again for your thoughts. I'll give it a shot and see what happens.

Denton


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John Fishback
Re: Mounting a jib into a truckbed
on Jul 4, 2009 at 6:04:01 pm

Another thought is to shorten the arm which should reduce the movement at its end. Shorter moment arm = less force at its end. Maybe the addition of some springs between the arm and base might dampen some vibration. Experiment with different attach points and strength springs.

John

MacPro 8-core 2.8GHz 8 GB RAM OS 10.5.5 QT7.5.5 Kona 3 Dual Cinema 23 ATI Radeon HD 3870, 24" TV-Logic Monitor
ATTO ExpressSAS R380 RAID Adapter, PDE Enclosure with 8-drive 6TB RAID 5

Final Cut Studio 2 (up to date)

Pro Tools HD w SYNC IO, Yamaha DM1000, Millennia Media HV-3C, Neumann U87, Schoeps Mk41 mics, Genelec Monitors, PrimaLT ISDN


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John Fishback
Re: Mounting a jib into a truckbed
on Jul 4, 2009 at 5:31:24 pm

Check this out. If you watch the camera, there are times it's shaking a lot. They must be using some kind of stabliztion. system.



John

MacPro 8-core 2.8GHz 8 GB RAM OS 10.5.5 QT7.5.5 Kona 3 Dual Cinema 23 ATI Radeon HD 3870, 24" TV-Logic Monitor
ATTO ExpressSAS R380 RAID Adapter, PDE Enclosure with 8-drive 6TB RAID 5

Final Cut Studio 2 (up to date)

Pro Tools HD w SYNC IO, Yamaha DM1000, Millennia Media HV-3C, Neumann U87, Schoeps Mk41 mics, Genelec Monitors, PrimaLT ISDN


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Liam Dewey
Re: Mounting a jib into a truckbed
on Jul 5, 2009 at 10:24:09 am

The new systems use electronic / computerized feedback gyro-stabilization, which is high-tech, complex and expensive.

The gyro feedback tells the remote controlled camera mount to move in the opposite direction of the shake / bounce, keeping a steady image.


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Liam Dewey
Re: Mounting a jib into a truckbed
on Jul 5, 2009 at 11:00:39 am

You need vibration dampers or isolators. I'm guessing they would be fairly expensive if you could find something that would work "off the shelf".

You might be able to DIY using cheap vehicle shock absorbers. Maybe. You would have to try it. I would try pneumatic shocks. Attach four (or at least three) to two plates, one plate attached to the truck, and the other to the jib. That might actually work well. And you might be able to DIY fairly cheaply and easily. So if it doesn't work, or work well enough, you aren't out a lot of money or time. (relatively speaking) That's just quickly off the top of my head.

Passive isolation would be cheapest, and maybe easiest, I think, and any active isolation (feedback with automated electro-mechanical compensation) would be more technical and difficult and probably (much) more expensive.

There is also the question of "simple vibration" versus "shock and bounce". (a relatively smooth road versus potholes, etc.)

Depending on how heavy the jib and camera setup are, you might be able to make your own fluid damper, by placing something inside of something else filled with water, and tied down so the two containers don't touch. (heavy duty rubber bungees? maybe with soft foam fillers (wet or dry) to help with lateral movement)

For example, if it was a tripod with a camera on it, you could use three cans that the tripod legs go in, with those in three larger cans filled with water, and the tripod "tied down" to the truck bed and sides with bungees so it can't really move, and is forced to float on the "bed of water". I would think that would work really well and pretty much remove all vibration, and small bounces.

Here's a link to a nice, expensive book that might be overkill for you, and a few other links that may or may not be of interest or value and/or give you some ideas, and then Google some of these terms I mentioned. Good luck.

http://catalog.asme.org/books/PrintBook/Passive_Vibration_Isolation.cfm

http://www.shopatron.com/product/part_number=7368/1323.0.42062.0.0.0.0

http://www.gelmec.co.uk/GelmecSiliconeGelStudMounts.htm

http://books.google.com/books?id=LoyyOWJzZiYC&dq=vibration+damping+or+isola...


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Mark D'Agostino
Re: Mounting a jib into a truckbed
on Jul 6, 2009 at 2:26:50 pm

While I've never attached a jib to the back of a truck I've had some luck simply letting some air out of the tires and running them soft. This would be in addition to other dampening ideas, not a replacement for.

Mark D'Agostino
http://www.synergeticproductions.com


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Steven Bradford
Re: Mounting a jib into a truckbed
on Jul 13, 2009 at 5:15:15 am

What Mark said. Plus, why are using a truck to begin with? That's 90% of your problem right there.

My students just failed miserably trying to do the same thing with a small jib. I wished they'd asked first, because the first thing I would have said was, don't use a truck. Use a convertible car. preferably a luxury or american car. Eldorados used to be great for this. Trucks, especially trucks that aren't carrying much of a load, are goind to transmit way to many shocks to the tripod. Letting the air out of the tire helps some.

Find a big old american car with a good size trunk, and remove the trunk lid. An old Town Car is perfect. You now have something very much like a pickup in back, but with a very smooth ride. After letting the tire pressure down to 22 or so.

Steven Bradford
http://www.3dstereomedia.com 3D company I've worked with since 1990
http://www.seanet.com/~bradford/ my personal home page, find my greenscreen page there.
http://www.seattlefilminstitute.com the school I teach at.


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